This invention relates generally to building panels and deals more particularly with a method for molding wall panels and to the construction of the molded panels.
In the construction of buildings, systems have been developed for prefabricating building panels and shipping them to the building site where they are assembled by construction workers. However, these types of systems have not been entirely satisfactory and have failed to a large extent to displace traditional xe2x80x9cstick builtxe2x80x9d construction techniques. One problem is that assembling the prefabricated panels and connecting them together requires cranes and other heavy equipment, as well as costly on-site labor. The materials of which prefabricated panels are constructed have been less than satisfactory in many respects, including their relatively high cost, heavy weight, lack of effective thermal insulation, structural deficiencies, and lack of resistance to fire, weather and insects. The panels that have been proposed in the past have also been difficult to finish other than by employing conventional techniques and materials.
The present invention is directed to a new building panel construction and to a unique method of molding panels either on-site or at a factory. The method is characterized by simplicity and makes use of uniquely formulated materials which provide the panels with structural strength, highly effective insulating properties, light-weight, surface layers that can be finished in virtually any desired manner, and resistance to fire, weather and insects.
In accordance with one aspect of the invention, a building panel can be molded by workers at the building site. A mold that has the desired panel first receives a relatively thin inside surface layer which is poured on the base of the mold in the form of a cement-gypsum blend mixed with a liquid catalyst. After the inside surface layer has hardened sufficiently, a reinforcing wire mesh is added to the mold, followed by pouring of a fire resistant layer which may be a blend of cement, gypsum and perlite mixed with a liquid catalyst. A metal stud framework is installed in the mold after the fire resistant layer has hardened, and insulation is applied to fill the stud cavities. Building paper and mesh reinforcement are secured to the stud framework, and an outer layer is then poured into the mold. Alternatively, another fire resistant layer may optionally be applied between the building paper and the mesh. Screws are used to attach the outside layer to the framework and, after the bottom of the mold has been removed, screws are used to fasten the inside layer to the studs.
It is a particular feature of the method of the present invention that mold inserts can be used in the mold in order to maintain one or more marginal areas of the framework exposed. This facilitates attachment of the molded panels to additional wall panels or to other structures.
Another important feature of the invention is that the mold has a specially constructed double panel bottom structure. This allows one of the bottom panels to be removed and screws to be applied through cutouts in the other panel to attach the inside surface layer to the framework before the second panel is removed.
In an alternative embodiment of the invention, a wire grid which is inserted into a mold includes two wire mesh panels spaced apart and parallel to one another. One or more edges of the grid are imbedded in spacers which maintain the wire mesh panels at the desired locations and also maintain the grid edge or edges exposed to facilitate their attachment to additional panels or other structures. A surface layer is poured into the mold to the depth of the lower grid panel and allowed to harden sufficiently before an insulating layer is poured into the mold to the depth of the other wire mesh grid panel. The final surface layer is poured last after the insulating layer has hardened. The result is a composite panel which is light in weight, highly insulating, and structurally strong by reason of the materials that are used for molding the different layers and the strength and reinforcement supplied by the wire gridwork.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.